Index: Lib/socket.py
===================================================================
--- Lib/socket.py	(révision 68329)
+++ Lib/socket.py	(copie de travail)
@@ -225,6 +225,8 @@
         return self._writing and not self.closed
 
     def fileno(self):
+        if self.closed:
+            raise error("I/O operation on closed socket")
         return self._sock.fileno()
 
     @property
@@ -239,9 +241,11 @@
         if self.closed:
             return
         io.RawIOBase.close(self)
+        self._sock._decref_socketios()
 
     def __del__(self):
-        self._sock._decref_socketios()
+        if not self.closed:
+            self._sock._decref_socketios()
 
 
 def getfqdn(name=''):
Index: Lib/test/test_socket.py
===================================================================
--- Lib/test/test_socket.py	(révision 68329)
+++ Lib/test/test_socket.py	(copie de travail)
@@ -856,6 +856,15 @@
         self.assertEqual(self.cli_file.mode, 'wb')
         self.assertEqual(self.cli_file.name, self.serv_conn.fileno())
 
+    def testRealClose(self):
+        self.serv_file.close()
+        self.assertRaises(socket.error, self.serv_file.fileno)
+        self.cli_conn.close()
+        self.assertRaises(socket.error, self.cli_conn.fileno)
+
+    def _testRealClose(self):
+        pass
+
 class UnbufferedFileObjectClassTestCase(FileObjectClassTestCase):
 
     """Repeat the tests from FileObjectClassTestCase with bufsize==0.
Index: Modules/socketmodule.c
===================================================================
--- Modules/socketmodule.c	(révision 68329)
+++ Modules/socketmodule.c	(copie de travail)
@@ -2007,6 +2007,10 @@
 static PyObject *
 sock_fileno(PySocketSockObject *s)
 {
+	if (s->sock_fd < 0) {
+		PyErr_SetString(socket_error, "I/O operation on closed socket");
+		return NULL;
+	}
 	return PyLong_FromSocket_t(s->sock_fd);
 }